Cf Viet Nam hien nay trong cac nha may hay xUdng ddng tau, thiic hien qua trinh tao hinh tam thep chu yeu dung phUdng phap gia cdng cd- nhiet do thie't bi cd gia thanh re, tuy nhien nd p
Trang 1Ufng dung he than kinh nhdn tao trong qud trinh
uon cong thep tdm bdng nhiet cam ufng
' Ks Tran Ihi Thuy Nga, ^PGS I S Tran Thu Ha, 'TS Nguyen TrUdng Thinh
'Cao ding Ky thuat Cao I bang, TR Hd Chi Minh Dai hgc SU pham Ky thuat TPHd Chi Minh
TOM TAT
Cng dung mgng thdn kinh nhdn tgo ggi tdt la ANN (artificial neural network) vdo phUdng phdp gia nhiet cdm dng nhdm dii dodn tga do diidng nhiet (heating-line) vd cdc tham so nhiet detgo hinh thep tdm theo hinh ddng mong muon mgt cdch de ddng hdn Vdi mo hinh ndy cdn cd tham sd nhap Id hinh dgng ban ddu cua tdm thep (gid tri nhap Id sii dfch chuyen theo phiidng ddng cua diem)
vd tham sd xudt Id vi tri diidng nhiet cdm dng dUdc liia chgn Cdc mdu hudn luyen cho ANN bang phiidng phdp phdn tich thu dUdc cho thdy cd the dU bdo dddc sii bien dgng cua tdm thep Trong gia nhiet cdm dng dd thd nghiem md hinh ANN dung dcxdc dinh vi tri dUdng nhiet tren be mat tdm thep khi tgo hinh cho ket qud khd khd quan
ABSTRACT
77t/5 paper presents the development of an artificial neural network model for the prediction of heating-line positions in induction heating process This model help shipyard manufacturers determine the positions of induction heating lines and their heating parameters to form a desired shape of plate The vertical displacements of plate have been considered as the input parameters and the selected induction heating lines as output parameters to develop the model The training patterns of neural network are obtained using an analytical solution that p"cdict: plate dcfcrir.ations in induction heating process The developed neural network model is tested to show its feasibility to determine the heating positions on the surface of aflat steel plate in the line heating process for forming a desired shape
% TAP CHI CO KHI VIET NAM < • Sd 11 (Thang 11 nam 2011)
Trang 2I G l 6 l THIEU
Trong cdng nghiep ddng tau thuy tao hinh
tam vd la mdt cdng doan quan trgng quyet dinh
den nang suat va chat lUdng vd tau Cf Viet Nam
hien nay trong cac nha may hay xUdng ddng tau,
thiic hien qua trinh tao hinh tam thep chu yeu
dung phUdng phap gia cdng cd- nhiet do thie't bi
cd gia thanh re, tuy nhien nd phu thudc vao ky
nang, kinh nghiem cua ngUdi thg khi dieu chinh
do cong cua tam thep theo y mudn, mat khac
lUdng nhiet sinh ra trong qua trinh ddt hdn hgp
khi oxy-axetylene cung nhU dac tinh tao nhiet
tfl qua trinh phan flng chay khdng de dang kiem
soat, viec ddt ndng trflc tiep cung anh hfldng den
chat Iflgng be mat chi tiet Trong kill dd, ddi vdi
cac loai tau cdng suat Idn, viec gia cdng vd tau ddi
hdi can phai dinh dang bien dang cd do chinh
xac cao, qua trinh dinh hinh bang dau ddt hdn
hgp khi oxy-acetylene chi cd the sfl dung gidi ban
trong mdt so iing dung, nen khdng the co hieu
qua cao De khac phuc, ta cd the sfl dung cam
flng dien tfl thay cho ngudn nhiet ndi tren So
vdi ngudn nhiet tfl md ban oxyacetylen, phfldng
phap cam flng dien tfl cd nhflng flu the nhfl de
dang dieu chinh va dieu khien Iflgng nhiet tren
tam thep khi gia cdng, do dd co the udn cong cac
tam thep cd be day khac nhau trong cdng nghiep
ddng vd tau, cung nhfl tai san xuat, khi phfldng
phap cam flng nhiet (p.p.c.fl) dfldc sfl dung vdi
thiet bi dieu khien cam flng tfl ddng va thuat toan
he dfldng nhiet nang suat se dfldc nang cad, ngoai
ra p.p.c.fl cdn cd the tich hdp vdi he thdng ngfldi
may trong tfl ddng hda
Do ta van chfla cd du cac cdng cu chuan
de xac dinh tham sd nhiet, vi tri dfldng nhiet khi
tao hinh hay de xac dinh do lech cua tam vdi
tham sd nhiet Nhflng nghien cflu trfldc day cung
chfla dfla ra dxiac giai phap chd viec xac dinh
Iflgng nhiet cam flng, hay sii di chuyen cua cudn
cam tren phdi gia cdng cung chfla dfldc md hinh
hda ve md phdng phfldng phap cam flng Vi vay
p.p.c.fl nhiet can dfldc md phdng 1 each chinh xac
de tien danh gia tinh kha thi khi flng dung vao
khau tao hinh cho thep tam vdi mdi lien he gifla
tga do dfldng nhiet va sfl bien dang cua tam thep theo yeu cau
Hinh 1; Cudn cdm cua mdy tgo hinh nhiet
bdng cdm iing
Trong nghien cflu nay, vdi nhflng cdng thflc ddn gian hda, md hinh mang than kinh nhan tao (ANN) dflgc gidi thieu tren cd sd phat sinh tga do dfldng nhiet va tham sd nhiet tfl be mat cong cua tam thep ANN la cdng cu tdi flu gan day dflgc flng dung trong md hinh hda cac van de thiic te phfle tap ANN dflgc lap trinh tfl nhflng phan tfl xfl li ddn gian tfldng hgp lien thdng day dac, cdn ggi la nd ron nhan tao cd kha nang thiic hien cac phep toan song song trong xfl li dfl lieu va bieu dien tri thflc Uu diem cua ANN xuat phat tfl dac tinh xfl li thdng tin dang chfl y cua he sinh hgc nhfl tinh phi tuyen, tinh song song, chap nhan va hgc hdi tfl cac ldi va sai
sd Muc tieu chinh cua mang tri tue nhan tao dfla tren nen tang tinh toan la phat trien cac thuat toan toan hgc kich hoat mang than kinh nhan tao hgc hdi bang each xfl li thdng tin va tiep nhan tri thflc tfldng tfl nhfl d bd nao ngfldi Cac quy trinh huan luyen cung nhfl thfl nghiem ANN da dflgc thiic hien vdi cac dfl lieu bien dang thu dflgc qua cac cdng thflc ddn gian hda la tga do nhiet va cac tham sd Md hinh ANN dflgc trien khai vdi gia tri nhap la hinh dang tam dfldc udn cong mong mudn de dfl doan dfldc tga do dfldng nhiet cam flng va cac tham sd nhiet Cac mau bien dang trong thiic nghiem va cac ket qua dfldc dii dddn trfldc bdi md hinh ANN da dfldc dem di so sanh vdi mau chuan cho thay tinh hflu dung va hieu qua cua phfldng phap de nghi trdng gia nhiet cam flng
TAP CHI CO KHI VIET NAM • Sd 11 (Thang 11 nam 2011)
Trang 32 P H A N T I C H DONG NHIET TRONG NHlfeT
CAMU^G
1 Phan tich sfl phat sinh dong nhiet
Cho ddng dien xoay chieu chay qua cugn
thien cd tan sd bang tan sd vdi ddng dien Neu dat tam thep trong tfl trfldng nay se xuat hien ddng dien cam flng (ddng dien phu-cd) trong tam thep
cd cung tan so nhflng trai chieu Ddng dien cam flng nay sinh ra mdt dic-n trd nhiet lam cho be mat tam thep ndng len do hieu flng Joule (hinh 2) Ta day se san sinh xung quanh nd 1 tu trfldng bien dung nhiet nay de udn cong tam thep
Vonq cam
Va: dAn dien
I linh 2 .\lo liiiili phii'iiii\> phap nhiet ciiiii ung
Hien tflgng dien tfl cd ban cua nhiet cam
flng da dfldc de cap den trong nhieu tai lieu Tuy
nhien trong md hinh hda gia nhiet cam flng tren
tam thep, hien tfldng dien tfl can chu y la tfl tinh
thay ddi theo nhiet do Do dd, md hinh toan hgc
cua nhiet cam flng thfldng cd cac hien tfldng vat
ly lien quan den la dien tfl , trao ddi nhiet va ca
hgc vat ran [2-3] Cd the ndi hien tflgng dien tfl
va nhiet do tren tam thep ludn anh hfldng qua lai
Md hinh ndi tren trfldc tien dflgc trien khai de
nham tao ddng nhiet tren tam thep trong sudt qua
trinh gia nhiet cam flng va sfl chenh lech nhiet do
tren tflng vung cua tam thep do tdc do di chuyen
cua cudn cam trong qua trinh gia nhiet cam flng
De ddn gian hda van de ve chuyen tiep ddng
nhiet, gia sfl tdc do di chuyen cua cudn cam
nhanh hdn nhieu so vdi sii dan nhiet Phfldng
trinh dieu chinh trfldng dien tfl va ddng nhiet
dflgc tinh toan bang phfldng phap phan tfl hflu
ban (FEM) thiic hien tren chfldng trinh sfl dung
ngdn ngfl FORTRAN Sii bien dang cua tam thep
bi han che do sii phat sinh bien dang deo trong
nhiet cam flng Gia thiet cho rang bien dang deo
dfldc sinh ra trong mdt khoang gidi han nhiet do
liic tac ddng da lam phat sinh bien dang gdc va do
CO ngang Nhiet do khdng dn dinh tren tam thep trong nhiet cam flng dfldc phan tich sd hgc qua cac phan mem ABAQUS, trong phan tich dien tfl sfl dung nhfl nhiet daiu vao tren tam thep Vung chiu nhiet do tdi han trong sudt qua trinh nhiet cam flng dfldc xac dinh la \ u n g ded rieng
2 Phan tich dong nhiet va bien dang nhiet:
De phan tich bien dang nhiet tren tam thep trong cam flng nhiet, dau tien can phan tich ddng nhiet khdng dn dinh Bang each xem dong nhiet phat sinh trong phan tich dien tfl nhfl dong
nhiet d\iac cung cap cho tam thep
Hieu flng truyen nang Ifldng tfl trfldng phu thudc vao khe hd khdng khi gifla cudn day
va tam thep (Nhiet Ifldng dfldc phan bd xung quanh cudn cam tuy thudc vao khoang each tfl vi tri ddng dien cua nd) Tfl phan tich thdng ke bang phfldng phap FEM dfla tren bien dang cua tam, ta
cd cdng thflc ddn gian de dii doan bien dang gdc vdi tham sd nhiet cho trfldc:
6^ = - 5 4 x 1 0 -^ +120.7(- 1 7^^\ 1353017(- - ) - (1)
\ ' — -•-'_• V
TAP CHi CO KHI VIET NAM • Sd 11 (Thang 11 nam 2011)
Trang 42 MO HINH D V D O A N D U d N G NHIET C A M
tfNG suf DUNG MANG TRI TUE N H A N TAO
ANNs la md hinh tinh toan, dflgc tai tao
tfl nhflng chflc nang cua mang sinh hgc, dflgc
tap hdp tfl nhflng nd ron va dflgc dung de giai
quyet nhflng chflc nang phfle tap trong nhieu
flng dung ANN bao gdm nhflng phan tfl xfl li
ddng bd ddn gian, lay y tfldng tu' he thdng than
kinh sinh hgc Mang than kinh nhan tao trinh
bay trong nghien cflu nay cd 3 den 4 ldp (layer):
ldp nhap, ldp xuat va 1 hoac 2 ldp an Ddn vi ca
ban cua ANN la nd ron, mflc do lien ket cua cac
nd ron gifla cac ldp dflgc dac trflng bdi trgng sd
lien ket, trong sd cac thuat toan huan luyen phd
bien nhat la thuat toan lan truyen ngflgc Mdi nd
ron trong ldp nhap nhan gia tri cua mdt bien ddc
lap va chuyen vao mang Dfl lieu tfl tat ca cac nut
trong ldp nhap dfldc tdng trgng hda va chuyen
ket qua cho cac nd ron trong ldp an Cac noron
ldp an khdng thiic hien tinh toan chflng chi ddng
vai trd lien lac vdi cac nd ron trong ldp nhap va
xuat Tfldng tfl cac noron trong ldp xuat cung
nhan cac tin hieu tdng trgng hda tfl cac nd ron
an Mdi nd ron trong ldp xuat tfldng flng vdi mdt
bien phu thudc
Trong gia nhiet cam flng, cac man bien
dang cua tam thep phu thudc vao sd Ifldng va
tga do cua dfldng nhiet Vi vay trong thfl nghiem
ANN dung de giai quyet van de neu tren, ANN
xac dinh tga do dfldng nhiet cam flng, be mat
dfldc nung ndng va van tdc cudn cam diia vao sfl
chuyen vi dflng cua cac nut tren tam thep bi bien
dang theo yeu cau
Xet tam thep hinh vudng phang chia
thanh d Ifldi, vdi n ' diem chia cd khoang each
bang nhau (Hinh 3)
n*1
2n*1
3n*1
(n-3)n* 1
(n-2)n*l
(n-1)n+1
)
i—r-n-2 n-1
—•—
1 •* t
I—* 4
L
x_^
2n
3n
4n
(n-2)n
(n-1)n
Hinh 3 Chia 6 lUdi cdc diem tinh todn chuyen vi ddng
Diem chuyen vi dflng thfl i cua d Ifldi dgc theo true U3 (hinh 4) la hi Do dd, mdi gia tri nhap cd n^ ddn vi bieu dien tam bi bien dang, the hien d mau tren d lUdi (nx n) bieu thi cac diem dich chuyen Bien dang gdc cua tam trong gia nhiet cam flng phu thudc vao cac tham sd van tdc nhiet, do day tam thep nhU cdng thflc(l)
'U3
* U1
Hinh 4 Tri sd djch chuyen nhap h cdc diem 6 liidi
cua tdm thep
De tam thep bien dang ldp xuat can dfldc xac dinh bdi cac tham sd nhfl sd Ifldng dfldng nhiet cam flng, be mat nung va van tdc Dfldng nhiet cd hdac khdng, be mat nung (mat trfldc hoac sau), va van tdc cudn cam
TAP CHI CO KHI VIET NAM • S d U (Thang 11 nam 2011)
Trang 5Theo nhfl hinh 5 dfldng nhiet cd the la
cac dfldng dgc, ngang hoac cheo, la cac dfldng di
chuyen cua cudn cam Tri sd cua ldp xual dfldc
bieu dien thed he nhi phan Mdi ddng nhiet cam
flng dflgc dii doan vdi 4 tham sd, dfldc trinh bay
nhfl bang I
Tliam sd 1- dfldng h\o nhiet: neu gia tr
bang 1 CO nhiet d dfldng cam flng nhiet va gia tr
0 khdng cd nhiel tai dfldng cam flng nhiet
Tbam sd 2- be mat: ne'u gia tri bang 1
nung ndng mat triioc \'a 0 dfldc nung ndng mat
sau
Tham sd 3 va 4 -van tdc: the bien 4 van
tdc cudn cam: chung dflgc ma hda 4 gia tri van tdc
(ma hda 00,01,10,11 va dfldng Ifldng 5,10,15,20
(m/s))
Bdng 1 Bien xudt cua dUdng nhiet cdm dng xudt
Tham sd
Tbam so 1
Tbam so 2
Tham so 3
Tham so 4
Gid
ti-i
0
1
0
1
0 0
0 1
1 0
1 1
Yn^iia
Nhiet cam iing
Vo nhiet cam iing Mat sau
Mat tnjoc Van toe thii nbat Van toe thii hai
\"an toe thii ba Van toe thii tur
Line 1
Line (n-1)/2
Line (n-1)/2 *1 Line (2n-2y2
Trong hinh 5 cd (3n-5) vi tri dfldng nhiet cam flng cd the phat sinh tren tam Do dd, cd (3n-5) dfldng dfldc sfl dung cho dii doan trong flng dung nay Mdi dfldng bao gdm 4 tham sd (minh
hga d bang I), vay cd 4(3n-5) gia tri xudt Khi
tham sd dau tien cua dfldng thfl / la 0, khdng co dfldng nhiet cam flng tai dfldng thfl i nen van toe
va be mat nung cung khdng tdn tai Do gia tri xuat cho mdi trfldng hdp md phdng chi cd the bang 1 hoac 0, nen gia trj xuat tinh dfldc sau khi mang so sanh vdi gia tri ngfldng:
Hinh 5 Sd do diidng nhiet cdm dng
Ldp nhap nhan (n2) gia tri chuyen vi dflng Ldp xuat cho ra tga do dfldng nhiet cam flng boat ddng, be mat nhiet va van tdc, sai lech dfldc tinh theo phfldng phap trung binh binh phfldng de ban che den mflc tdi thieu ldi
Mdt trong sd nhflng nhiem vu quan trgng trong nghien cflu ANN la xac dinh kien true mang tdi flu, lien quan den cac ldp an va nd ron ben trdng nd Cau true ANN cd nhflng hieu qua dang ke trong dfl doan ket qua Tuy nhien, so Ifldng ldp an tdi flu va nd rdn tdi flu trong moi ldp cdn tuy thudc vao tflng trfldng hdp cu the va khdng cd phfldng phap ddn gian nao de xac dinh chflng Thdng thfldng, chay thfl va tiep can loi
la phfldng phap hay dung Nhieu ldp an vdi cac mau dac trflng phii thudc vao sd mau huan luyen
va do chinh xac khi phan ldp Theo ly thuyet, cac ket qua cho thay 1 ldp an du cho 1 thuat toan lan truyen ngfldc anh xa bat ky dfl lieu nhap nao vao mdi dfl lieu xuat trong do chinh xac tuy y Trong trfldng hdp nay, ANN the hien (n^) gia tri dich chuyen dflng cua tam nhfl cac bien nhap, va cac dfldng tinh tddn trong sd (3n-5) dfldng nhiet cam flng dfldc xem la bien xuat Cac ddn vi nhap trong mang dfldc lien ket vdi ldp xuat qua 1 ldp an vdi
pi nd ron Trong ca sd dfl Heu, gia tri nhap thi
lien tuc cdn gia tri xuat la nhi phan Nhan td quan trgng trong md hinh ANN la ham truyen dang
TAP CHI CO KHI VIET NAM • Sd 11 (Thang 11 nam 2011)
Trang 6sigmoid dung kich boat cho nhieu ldp khac nhau
do kha nang dii doan bien dang tdt hdn nhflng
ham truyen khac
3 KET QUA VA T H A O LUAN
Chfldng trinh xfl li ANN dfldc viet bang
ngdn ngfl Fortran, sfl dung dfl lieu tfl cdng thflc
ddn gian (1) nham tim cac gia tri trgng sd cua cac
ldp khac nhau Md hinh mang than kinh nhan tao
danh gia mdi quan he gifla cac dang tam mau va
tga do ddng nhiet cam flng da dfldc thie't lap Muc
dich cua md hinh nay la giai quyet cac van de ve
xac dinh sd Iflgng dfldng nhiet cam flng vdi tat ca cac tham sd cua nd bang cac dfl doan diia tren ANN
Mdt sd trfldng hgp thfl nghiem dflgc danh gia bang cac ket qua dfl doan cua ANN, ddi chieu vdi ket qua mong mudn cua tam thep cd kich thfldc ban dau (1000x1000x20) mm3 dflgc chia d Ifldi cd khoang each gifla 2 diem tren mang tinh toan do dich chuyen la 100mm Cau trflc ANN dflgc xay diing vdi 121 gia tri chuyen vi dflng cua tam la bien sd nhap, minh hga d hinh 6, va cd 28
vi tri dfldng nhiet cam flng cd the cd nen bien xua't dflgc tao lap la 112 gia tri, minh hga d hinh 7
T TJ "S p — ^
12 \13 u 15
.2^ - ^ 2 ^ - ^ 2 5
34
> - - 1
46
SS
67
35 36
1 • — -(
46 47
37
• A
48
s — ' ,16
i^^
38
, ,
49
28
19
29 ;^30
39 \40
h -f-
SO I s f
I j
S7 [se 59 ^60 161 162
f t • * <•
,68 ^69 70 71
i
78 [73
89 190
100 I 101
111 112
I
72 '73
^ • • t T "
80 f.31 8 2 ,83 l84
m
J02
32
103
93
104
^113 \l14 I f f S
94
105
0 2 ^
95
106
SU-
52
63
J"* 1
SS ,
96
107 ^
• U i ^
•3 '
20
3f
42
I 1
53
64
/ 5
86
97
108 ,
JIL^
,32
43
> '
54
65
7®
87
98
^109
J^
11
22
33
88
121
^ ^ lOOx 100
Hinh 6 Sd do cdc diem nut cho mo hinh ANN
Mdt trong sd nhflng khau quan trgng nhat
trong nghien cflu ANN la xac dinh cau true mang
tdi flu, lien quan den sd Ifldng cac ldp an va nd
ron trong nd Sd Ifldng nd ron trong cac ldp an
dflgc xac dinh qua chay thfl va phfldng phap tiep
can ldi, nham dieu tiet cac ldi ddng quy Trong
nghien cflu nay, cau trflc tdi flu cua mang than
kinh dat dfldc bang each thfl sd ldp an va nd ron
khac nhau Cau true ANN bao gdm 1 - 2 ldp an
vdi cac nd ron khac nhau trong ldp an dfldc kiem
tra Thfl nghiem khdi ddng 1 ldp an vdi 50 noron,
va do chinh xac cua gia tri dii doan da dfldc kiem
tra trfldc cau true tdi flu cua mang ANN lfla chgn
Muc tieu de tang den mflc tdi da do chinh xac
7000
Hinh 7 Sd do diidng nhiet cdm dng cho md hinh ANN
nham dat dfldc 1 mang ANN the he tdt nhat
Sau khi thfl nghiem, thay rd sfl gia tang Iflgng nd ron dung trong ldp an khdng he giup cai tien mang, 1 ldp an ddn cho ddng quy tdt hdn
2 ldp an khi dfl doan dfldng Dfl doan nhiet cam flng dat do chinh xac cao nhat khi sfl dung mang vdi 1 ldp an cd 160 nd ron Nhfl vay, nhieu nd ron trong ldp an khdng dam bao cho viec giam cac ldi trong thfl nghiem binh thfldng hay giup lam tang do chinh xac Diia tren phan tich dd, cau true tdi flu cua ANN dfldc tao lap la 121-160-112 flng vdi dfl lieu nhap, noron trong ldp an va sd dfl lieu xuat Md hinh cd cau true sau:
cr=
TAP CHI CO KHI VIET NAM • S d l l (Thang 11 nam 2011)
Trang 7- Sd Ifldng nd ron ldp nhap = 1 2 1 ,
- Sd Ifldng ldp an = 1
Sd Iflgng nd ron ldp an = 160
Sd chu ki huan luyen = 10.000
So Iflgng nd ron ldp xiuil = 112
Dii lieu huan luyen vdi 1.200 man cd
so du' lieu, dua tron moi quan lie gifla cac hinh
dang khac nhau cua taim vii vi tri dfldng nhiet
cam flng, cung nhfl \an ldc \'a be mat nhiet cua
chung, dugc chia ngau nhien thanh 2 bd thdng
ke: huan luyen xa kiem tra Trong dd 800 dfl lieu
dflgc dung cho huan luyen \-i\ 400 cho kiem tra
Dich chincii thang theo true / tai cac diem tren
tam thep dflgc tinh loan nhfl dfl lieu nhap theo
cdng thflc (1), Trong trfldng hdp nay, mang than
kinh huain luyen, co sd dfl lieu dflgc su dung
ngau nhien de xac dinh gia tri trgng sd va biased
Ti le hgc hdi dflgc dinh d mflc 0.2 va he sd ddng
Ifldng d 0.8 Huan luyen dfldc thiic hien chd den khi dai 10000 lan va sai sd la 0,0001 Tai thdi diem bat dau huan luyen, ANN khdi ddng khdi Ifldng mang vdi I tap hdp nhd cac gia tri ngau nhien theo Nguyen - Widrow [4] Trong sudt mdi vdng lap, mang nhan dfldc I ma tran trgng
sd Sau do, he thdng tinh tdng cac sai sd binh phfldng gifla dau ra mong mudn va dau ra thtfc
te cua mang Dung chenh lech cua tdng nhap vao trgng sd mang de sai sd nhd hdn trong mdi vdng lap tiep theo Do chinh xac cua md hinh trien khai phu thudc vao cac trgng sd nay Huan luyen ket thuc khi tdng cac sai sd binh phfldng dfldi ngfldng cho phep, dat dfldc trgng sd tdi flu Mat den vai gid cho xfl li toan hgc trong huan luyen
de thu dugc trgng sd tdi flu va gia tri sai lech
Tuy nhien, chi mat cd vai giay de thflc hien mo phdng Day la 1 kha nang vfldt trdi cua mang ANN trong cdng tac dfl doan
to IJ
-10
v^?&!
•''?5^
-^ 500^
500
fy
^ -'00 I ^ ^
^ ^ 1 * * 1 1 1 y * 1 1 t s
1 1 1 , ' i 1 1 1 / 1 1 1 i,»
, » 1V- 1 1 1 / l 1 1 1 , ' 1
iP-i ^ — i _ - j < ^ _ i _ _ 4 | _ J t _ _ i —
' ' 1 - ^ 1 / ' • ' 1 , ' 1 1
- _ J 1 lisiC-L _ i_ _ J- _ J ' - _ i _ _ i _ _
1 1 / i w ' ' ' » * ' ' '
1 U ^ 1 - 1 1 L.» 1 1 I _,
T ^ - - \ - - - - r - * T — r — 1 — r j ^ 1 / 1 1 1 1 5 1 * 1 1 1 i /
~ y^ "f "1 r- , * r w r -r - i
yf-/ i 1 1 1 * ' 1 ^ 1 1 l yf-/ I
^f-^ f _ _ , _ _ ^ _ , _ _ ^ f _ y ^ _ ^ _ 4 i - - * i - 1 t- - 4 -j<- -1 1
1 1 • 1 1 1 1 / i V9I 1
- - J - _ > l - i _ - i _ _ i _ _ i < a _ i ) _ _ i _ _ ,
1 » ^ 1 1 1 > n 1 1 1 r»
i.'l4 l '- J ^ ' ' ' ""His ,*r 7—1—r>r-T r—i-^-^r;
500
>
X
»
•500 y d K i s
(a) Tdm bien dgng mong mudn
i # Front surface heat line V = 5 tn/s V = 15 m/s
• - - • Back surface heat line V = 10 m/s V = 20m/s
(b) Du dodn dudng nhiet vd cdc tham sd
Tfl hinh dang tam mong mudn cd chuyen
vi dflng cua cac diem minh hga hinh 8a Gia tri
cua chflng dxiac Iflu gifl tai vec td nhap de md
phdng ANN, sau md phdng ket qua cho ra sd
dfldng nhiet vdi cac gia tri 0 hoac 1 (thfldng sd
dfldng nhiet it hdn 28) dfldc ve lai tren tam nhfl
hinh 8b , cac dfldng cham bieu hien nhiet cam
flng d tren mat sau cua tam, va cac dudng lien
d mat trfldc Dau tien cac tham sd nhiet cua 28
dfldng dfldc kiem tra, khi tham sd dfldng nhiet dii
Hinh 8 DU lieu nhdp va xudt trong 1 tntdng hdp cu the
bao la 1, cac dfldng dfldc nung ndng bang nhiet cam flng, thi cac tham sd khac thudc dfldng nay
se dfldc kiem tra, khi cac dfldng dfldc dii doan la
0, chung khdng dfldc nung ndng bang nhiet cam flng, cac tham sd cung khdng dfldc xet
Thi nghiem tren tam thep ban dau cd dang phang, sau khi dfldc nung theo 5 dfldng do ANN dfl doan (hinh 9) Gia tri chuyen vi dflng cua tam tai cac diem dfldc do bang May do 3 chieu CMM
TAP CHI CO KHI VIET NAM < • So 11 (Thang 11 nam 2011)
Trang 8i
Hinh 9: Ddng nhiet cdm dug d mat tntdc (a) vd mat sau (b) trong thi nghiem
Ket qua mong mudn va ket qua thi -500 (mm), -300 (mm), -100 (mm), 100 (mm), nghiem sau khi nung cam flng cua tam thep 300 (mm) va 500 (mm) dflgc the hien bang cac dfldc kiem tra tai mdt sd vi tri mat cat cd tga y= bieu dd hinh 10
Vertical deflechon of plat? i l y = -500 mm Vertical defledion of plale at y=-300 mm
-400 -300 -:JJ -m 0 100 200 300 400 500
I (mm)
/'eiticalr!?lleritriri of plate at y = -I00mm
'-500 400 -300 -2C0 -100 0 100 200 300 400 500
x(mm)
-E^pe^imetal result
•500 -m -300 -200 -lOO 0 100 200 300 iCC 5C';
* (mm)
Verticaldeflection ofplale i l y = I 0 O m m Verttcai deflection of plate at y = 300 mm e'licjldellecliof) of plate al y = S)Omm
•400 -300 -200 -100 0 100 200 300 400 500
K(mm)
-400 -300 -200 -100 0 100 200 30O
X (mm)
-500 -400 -300 -200 -100 0 100 200 300 400 500
x(mm)
Hinh 10, Chuyen vi diing ciia diem tren tdm thep dUdcgia nhiet cdm itng ci=
TAP CHI CO KHI VIET NAM V S6 11 (Thang 11 nam 2011)
Trang 9Mac du van tdn tai mdt vai sai sd gifla 4 KET LUAN
cac gia tri chuyen vi mong mudn vdi gia tri thfl
nghiem, dang tam dfl doan kha gidng vdi dang Ndi dung chinh cua nghien cflu dfldc tdm tam mdng mudn Nguyen nhan gay nen su khac tat nhfl ,sau:
biet cd the do:
Cdng thflc ddn gian giup md phdng bien
Sd dfl lieu huan luyen va phan phdi dang tam I each de dang trong nhiet cam flng ngau nhien chfla dfldc chuan bi tdt cho cac dfldc phat trien vdi cac phfldng phap FEM cua
tham sd dfl doan trong trfldng hgp n^y Dc cai cd nhiet Md phdng va thfl nghiem da thu dxiac
thien tinh hinh, md hinh ANN non dflOc huan nhieu ket qua gidng nhau
luyen vdi sd dfl lieu Idn hdn va man dflgc chgn Md hinh ANN cd kha nang dfl doan dfldng cap ngau nhien phan phdi deu hdn, cung nhfl td nhiel vdi nhflng tham sd nhiet can thiet da dfldc hdp nhieu hdn 10 dfldng nhiet phat trien vdi cac thuat toan lan truyen ngflgc
Kha nang flng dung nghien cflu da chflng minh Chenh lech gifla -4 van tdc dflgc chgn md hinh nay la cdng cu dfl doan giup xac dinh qua Idn, do dd chung cd the lam anh hfldng tdi dfldng tao nhiet tfl cac yeu cau trong thflc te san sai sd tren taim bien dang De giam cac sai sd, xuat hinh dang cua tam thep trong phfldng phap
sd cac bit ma hda van tdc dflgc dung Idn hdn 2, cam flng nhiet
hoac khac biet gifla 2 van tdc nen nhd hdn Md hinh phat trien cd the giam thdi gian giai
quyet van de lam each nao de trung khdp sfl dich Cac dieu chinh se giup mang dfla ra chuyen cua tam thep vdi tga do ddng nhiet cam ket qua dfl doan dfldng nhiet chinh xac hdn flng va van de ve dfl bao dfldng nhiet cam flng Tuy nhien, ket qua hien tai cung cho thay, md Thuat toan cua ANN dat dfldc trdng nghien cflu hinh ANN dflgc trien khai cd the giflp dii doan nay- thuat toan ve phat sinh ddng nhiet cam flng dfldng nhiet cam flng tfl cac chuyen vi dflng , bang each nao va d dau de nung phdi gia cdng -thiic sii nd la mdt cdng cu tdi flu giup thie't lap hoan toan phu hdp va dang tin cay de cd the ap quan he gifla chuyen vi dgc va dfldng nhiet cam dung gia nhiet cam flng vao cac tam thep Idn hdn
ling va nhieu dfldng hdn •
Tai lieu tham khao:
[1] Valery Rudnev, Don Loveless, Raymond, Micab Black, "Handbook of Induction Heating," Marcel Deckker 2003
[2] Y Favennec, V Labbe, F Bay, "Induction heating processes optimization a general optimal control approach," Journal of Computational Physics 2003; 187: 68-94
[3] Alexandre Masserey Jacques Rappaz, Roland Rozsnyo, Rachid Touzani, "Power formulation for the optimal control of an industrial induction heating process thixoforming," International Journal of Apphed Electromagnetics and Mechanics 2004; 19: 51-56
[4] Derrick Nguyen, Bernard Widrow, "Improving the learning speed of 2-layer Neural Networks by choosing initial values of the adaptive weights," Proceedings of the International Joint Conference on Neural Networks, San Diego, 1990
TAP CHI CO KHI VIET NAM < • S d l l (Thang 11 nam 2011)